@pasquelin/panels

Live demo ↗ · Documentation 🇫🇷 · Documentation 🇬🇧 · MIT

A React panel chassis: icon rails on the edges, resizable zones around a free centre, and a layout that survives a reload.

It is a layout, not a framework. What goes in the panels is your project's business — the library draws the frame, remembers the sizes, and gets out of the way.

pnpm add @pasquelin/panels

import { Panels, Panel } from '@pasquelin/panels'
import '@pasquelin/panels/styles.css'

type PanelId = 'files' | 'chat'

export function App() {
  return (
    <Panels<PanelId>>
      <Panel<PanelId> id="files" zone="left" title="Files" icon={<FilesIcon />}>
        <FileTree />
      </Panel>

      <Panel<PanelId> id="chat" zone="right" title="Assistant" icon={<ChatIcon />}>
        <Conversation />
      </Panel>

      <Panels.Center>
        <Outlet />
      </Panels.Center>
    </Panels>
  )
}

That is the whole of it. The rails, the resize handles, the persistence and the keyboard are already there.

What you get

• Five zones — left, right, top, bottomLeft, bottomRight. A zone nobody fills takes no room at all. top is a band across the width and has no rail of its own: the project opens and closes it.
• Two halves per zone — primary and secondary, parted by a handle. Panels sharing a half take turns; the rail switches between them.
• Icon rails that stay put when a zone closes, so a closed panel is always one click away.
• Resize by pointer or keyboard, clamped so the centre never disappears.
• Persistence to localStorage out of the box, or wherever you say.
• Draggable rail icons, opt-in: draggablePanels lets a reader move a panel into another half, and where they put it is remembered.
• Typed ids — reveal('chatt') does not compile.
• No dependencies beyond React. No icon set, no CSS framework, no i18n.

Panel props

Prop	Meaning
id	Unique, and the type parameter of <Panels>
zone	Which edge it hangs from
slot	primary (nearest the edge) or secondary. Defaults to primary
title	Accessible name and header title, already translated
icon	Anything React renders — the library imposes no icon set
actions	Rendered on the panel's own title row
opens	The width this panel wants when it leads its zone
solo	Takes the zone whole; the other half is put away, not closed, and comes back

Driving the panels from anywhere

usePanels() is all a header, a shortcut or a menu needs:

const { panels, reveal, close, toggle, isShown } = usePanels<PanelId>()

From outside React — a socket message, an Electron menu — build the store yourself and keep the reference:

const store = createPanelsStore<PanelId>()

socket.on('alert', () => store.getState().show('alerts'))

<Panels<PanelId> store={store}>…</Panels>

Making it yours

Three levels, and you can stop at any of them.

1. Repaint it. Every value is a custom property on .pnl-root:

.pnl-root {
  --pnl-panel: #101418;
  --pnl-chassis: #1b1f24;
  --pnl-accent: #47965c; /* the rails follow your brand */
  --pnl-radius: 10px;
  --pnl-rail: 56px;
}

2. Replace a piece. Rail, PanelHeader, ResizeHandle, Surface, IconButton and the rest are exported. Build your own frame out of the ones you keep.

3. Take the logic only. Every component is built on hooks that render nothing:

const zone = useZone('left') // what it draws, its size, its split
const { reveal, isShown } = usePanels()
useContainerFit(ref) // re-clamps when the container resizes

Draw whatever you like on top. The chassis has no opinion about it.

It fits inside your page

The chassis measures its own container, never the window. Put it in a route, under your navigation, beside your sidebar — the clamps follow the box it is actually in.

Header and footer are yours

<Panels> draws no chrome. header and footer are slots; pass your own, or nothing. Where a project's panels come from — a router, a state machine, a config — is that project's business.

Examples

All four run at pasquelin.github.io/panels, or locally:

pnpm dev

• examples/minimal — the smallest working chassis
• examples/router — the centre as a React Router outlet
• examples/dockview — document tabs, on the optional Dockview entry point
• examples/theme — the same chassis under four palettes

Documentation

	🇫🇷 Français	🇬🇧 English
Guide + index	docs/fr/	docs/en/
Panels	PANELS.md	PANELS.md
Layout	LAYOUT.md	LAYOUT.md
Hooks	HOOKS.md	HOOKS.md
Theming	THEMING.md	THEMING.md
Components	COMPONENTS.md	COMPONENTS.md
Document tabs	DOCKVIEW.md	DOCKVIEW.md
Recipes	RECIPES.md	RECIPES.md
Architecture	ARCHITECTURE.md	—

For coding agents: llms.txt is the mental model, the API and the traps in one page; llms-full.txt is every English chapter concatenated. Both ship with the package, and pnpm llms regenerates the second from the first plus docs/.

Releasing

main is production; develop is where work lands. A release is a tag:

npm version patch      # or minor / major — bumps, commits, tags
git push --follow-tags

The tag triggers release.yml, which checks that it matches package.json, replays pnpm validate, builds, and publishes to npm with a signed provenance attestation — over OIDC, with no token anywhere. See CHANGELOG.md for what shipped.

Licence

MIT — see LICENSE.

Every dependency is MIT too, so there is no copyleft obligation anywhere in the tree. zustand is bundled into the published package and its notice travels with it; everything else is a peer dependency the consuming project installs itself. The full accounting is in THIRD-PARTY-NOTICES.md, and pnpm licences:check fails the build if it stops being true.